And by the G-men, I mean the guys knocking-in your door right now (Wired Blog):

DarkMarket.ws, an online watering hole for thousands of identify thieves, hackers and credit card swindlers, has been secretly run by an FBI cybercrime agent for the last two years, until its voluntary shutdown earlier this month, according to documents unearthed by a German radio network.

Reports from the German national police obtained by the Südwestrundfunk, Southwest Germany public radio, blow the lid off the long running sting by revealing its role in nabbing a German credit card forger active on DarkMarket. The FBI agent is identified in the documents as J. Keith Mularski, a senior cybercrime agent based at the National Cyber Forensics Training Alliance in Pittsburgh, who ran the site under the hacker handle Master Splynter.

The NCFTA is a non-profit information sharing alliance funded by financial firms, internet companies and the federal government. It’s also home to a seven-agent FBI headquarters unit called the Cyber Initiative and Resource Fusion Unit, which evidently ran the DarkMarket sting.

The FBI didn’t return a phone call Monday.

[…]

Threat Level admires Lord Cyric’s bluster, but thinks his days in the underground are numbered. The FBI almost certainly closed DarkMarket in preparation for a global wave of arrests that will unfold in the next month or so. The site was likely shuttered to avoid an Agatha Christie scenario in which a diminishing pool of cybercrooks are free to speculate about why they’re disappearing one-by-one like the hapless dinner guests in Ten Little Indians.

I do believe that the FBI is yelling “w00t” at all the information they have obtained on the “l33t” hackers.